Tension member routing designs to achieve transcatheter stented prosthesis compression

ABSTRACT

The present disclosure relates to delivery devices for transcatheter stented prosthesis loading, delivery and implantation. The delivery devices provide a loaded delivery state in which the stented prosthesis is loaded and compressed over the delivery device. The compression of the stented prosthesis can be adjusted with one or more elongate tension members, which extend around the stented prosthesis and proximately to an actuation and release assembly that can be provided as part of a handle assembly. The delivery device can be manipulated to adjust tension in the tension members to permit the stented prosthesis to compress, self-expand, and ultimately release from the shaft assembly. In some embodiments, the tension in one or more tension members is adjusted with one or more actuation and release assemblies.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of Ser. No. 16/995,351,filed on Aug. 17, 2020, now allowed, which application is a divisionalapplication of Ser. No. 15/938,576, filed on Mar. 28, 2018, now U.S.Pat. No. 10,772,749, which claims the benefit of the filing date of U.S.Provisional Patent Application Ser. No. 62/477,516, filed Mar. 28, 2017,the entire contents of which are incorporated herein by reference.

BACKGROUND

This disclosure relates to delivery devices and components for atranscatheter stented prosthesis, such as a stented prosthetic heartvalve.

A human heart includes four heart valves that determine the pathway ofblood flow through the heart: the mitral valve, the tricuspid valve, theaortic valve, and the pulmonary valve. The mitral and tricuspid valvesare atrio-ventricular valves, which are between the atria and theventricles, while the aortic and pulmonary valves are semilunar valves,which are in the arteries leaving the heart. Ideally, native leaflets ofa heart valve move apart from each other when the valve is in an openposition, and meet or “coapt” when the valve is in a closed position.Problems that may develop with valves include stenosis in which a valvedoes not open properly, and/or insufficiency or regurgitation in which avalve does not close properly. Stenosis and insufficiency may occurconcomitantly in the same valve. The effects of valvular dysfunctionvary, with regurgitation or backflow typically having relatively severephysiological consequences to the patient.

Diseased or otherwise deficient heart valves can be repaired or replacedusing a variety of different types of heart valve surgeries. Oneconventional technique involves an open-heart surgical approach that isconducted under general anesthesia, during which the heart is stoppedand blood flow is controlled by a heart-lung bypass machine.

More recently, minimally invasive approaches have been developed tofacilitate catheter-based implantation of the valve prosthesis on thebeating heart, intending to obviate the need for the use of classicalsternotomy and cardiopulmonary bypass. In general terms, an expandablevalve prosthesis is compressed about or within a catheter, insertedinside a body lumen of the patient, such as the femoral artery, anddelivered to a desired location in the heart where the valve prosthesisis then deployed.

The disclosure presents improvements related to the above.

SUMMARY

The present disclosure relates to delivery devices for transcatheterstented prosthesis loading, delivery and implantation. Such deliverydevices can include, for example, an optional outer delivery sheathassembly, a shaft assembly and a handle assembly. The delivery devicesprovide a loaded delivery state in which the stented prosthesis isloaded and compressed over the shaft assembly. Compression of thestented prosthesis can be adjusted with one or more elongate tensionmembers, which extend around the stented prosthesis and proximately toan actuation and release assembly, which can, in some embodiments, beprovided in the handle assembly. The delivery device can be manipulatedto adjust tension in the tension members to permit the stentedprosthesis to compress, self-expand, and ultimately release from theshaft assembly.

Various disclosed embodiments can include one or more balancing elementsor are otherwise configured to distribute the tension applied to thetension members to provide even crimping and expansion of the stentedprosthesis. In embodiments where only one tension member is provided,various disclosed balancing elements can distribute the tension appliedalong a length of the tension member. In certain embodiments, thebalancing element interconnects the one or more tension members to anactuator that can be withdrawn proximally to tension one or more tensionmembers. The balancing element defines an aperture formed in orconnected to the actuator, for example, in which the at least onetension member can slide. In this way, each tension member willnaturally slide as the actuator tensions and adjust the length oftension member positioned around the stented prosthesis so that thetension applied by each balanced tension member to the stentedprosthesis is generally equal both between tension members connected tothe balancing element and along a length of the tension member if onlyone tension member is employed to compress multiple areas of the stentedprosthesis. In various embodiments, the balancing element is a ringinterconnecting a plurality of tension members, wherein the balancingelement is separate from the actuator. In further embodiments, multiplebalancing elements are provided.

As discussed above, various embodiments include one an actuation andrelease assembly. The actuation and release assembly can optionallyadjust the tension in two or more tension members simultaneously. Inother embodiments a plurality of an actuation and release assemblies areprovided to either simultaneously or individually actuate a plurality ofrespective tension members. In such embodiments, one or more balancingelements can be incorporated into the delivery device to balance thetension within one or more tension members as the actuation and releaseassemblies vary tension in the respective tension members.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example of a delivery device fordelivering a stented prosthesis.

FIG. 2A is a schematic illustration of the delivery device of FIG. 1having the stented prosthesis positioned over an shaft assembly of thedelivery device in a compressed arrangement with a plurality of elongatetension members.

FIG. 2B is a schematic illustration of the delivery device of FIG. 2Ahaving the stented prosthesis positioned over the shaft assembly of thedelivery device in an expanded arrangement with the plurality ofelongate tension members.

FIG. 3A is a perspective view of one stented prosthesis, a stentedprosthetic heart valve, that can be used with the delivery devicesdisclosed herein shown in the expanded arrangement.

FIG. 3B is a front view of the stented prosthesis of FIG. 3A in thecompressed arrangement.

FIG. 4 is a schematic illustration of how three elongate tension memberscan be releasably positioned around a stented prosthesis with a releasepin and tension in the tension members can be adjusted with a singleactuator (the stented prosthesis is not shown for ease of illustration).

FIG. 5 is a schematic illustration of an alternate way in which a singleelongate tension member can be releasably retained around a stentedprosthesis (the stented prosthesis is not shown for ease ofillustration).

FIG. 6 is a schematic illustration of yet another way in which a singleelongate tension member can be releasably retained around a stentedprosthesis (the stented prosthesis is not shown for ease ofillustration).

FIG. 7 is a schematic illustration of a way in which multiple elongatetension members can be releasably retained around a stented prosthesis(the stented prosthesis is not shown for ease of illustration).

FIG. 8 is a schematic illustration of another way in which multipleelongate tension members can be releasably retained around a stentedprosthesis (the stented prosthesis is not shown for ease ofillustration).

FIG. 9 is a schematic illustration of a way in which two elongatetension members can be releasably retained around a stented prosthesis(the stented prosthesis is not shown for ease of illustration).

FIG. 10 is a schematic illustration of a way in which a plurality ofelongate tension members can be releasably retained around a stentedprosthesis (the stented prosthesis is not shown for ease ofillustration).

FIG. 11 is a schematic illustration of a way in which three elongatetension members can be releasably retained around a stented prosthesis(the stented prosthesis is not shown for ease of illustration).

FIG. 12 is a schematic illustration of a way in which four elongatetension members can be releasably retained around a stented prosthesis(the stented prosthesis is not shown for ease of illustration).

FIG. 13A is a schematic illustration of yet another way in which aplurality of elongate tension members are releasably positioned around astented prosthesis with a release pin and tension in the tension membersis balanced with a balancing element (the stented prosthesis is notshown for ease of illustration).

FIG. 13B is an enlarged schematic illustration of Sec. 13B of FIG. 13Aillustrating the connection between the tension members and thebalancing element.

FIG. 14 is a schematic illustration of one way in which two elongatetension members can be positioned around a stent frame (shownschematically in phantom).

FIG. 15 is a schematic illustration of a way in which three elongatetension members can be positioned around the stent frame (shownschematically in phantom).

FIG. 16 is a schematic illustration of a way in which three elongatetension members can be positioned around a stented prosthesis (thestented prosthesis is not shown for ease of illustration).

FIG. 17 is a schematic illustration of a way in which three elongatetension members can be positioned around a stented prosthesis (thestented prosthesis is not shown for ease of illustration).

FIGS. 18-19 illustrate a way in which a single elongate tension membercan be releasably positioned around a stented prosthesis such that asthe tension member is tensioned, ends of the stented prosthesis compressbefore a waist section of the stented prosthesis (the stented prosthesisis not shown for ease of illustration in FIG. 18 , however, variousportions of the elongate tension member are shown in phantom toillustrate dimension if the tension member was routed around a stentedprosthesis).

FIG. 20 is a schematic illustration of a way in which a single elongatetension member can be releasably positioned around a stented prosthesissuch that as the tension member is tensioned, ends of the stentedprosthesis compress gradually compressing the profile down at a waist ofthe stented prosthesis (the stented prosthesis is not shown for ease ofillustration, however, various portions of the elongate tension memberare shown in phantom to illustrate dimension if the tension member wasrouted around a stented prosthesis).

FIG. 21 is a partial, schematic illustration of one balancing elementthat can be used with the embodiments disclosed herein.

FIG. 22 is a partial, schematic illustration of an alternate balancingelement that can be used with the embodiments disclosed herein.

FIG. 23A is a partial, front view of an alternate balancing element thatcan be used with the embodiments disclosed herein.

FIG. 23B is a partial, side view of the balancing element of FIG. 23B.

FIG. 23C is a partial, schematic, cross-sectional illustration of thebalancing element of FIGS. 23A-23B.

FIG. 24 is a partial, perspective view of yet another balancing elementthat can be used with the embodiments disclosed herein.

FIG. 25 is a partial, perspective view of a further balancing elementthat can be used with the embodiments disclosed herein.

FIG. 26 is a schematic illustration of an alternate delivery devicehaving a plurality of actuators to control a plurality of elongatetension members.

FIGS. 27A-27C are schematic illustrations of the delivery device of FIG.26 being used to deliver and implant the stented prosthesis of FIGS.3A-3B to a valve.

DETAILED DESCRIPTION

Specific embodiments of the present disclosure are now described withreference to the figures, wherein like reference numbers indicateidentical or functionally similar elements. The terms “distal” and“proximal” are used in the following description with respect to aposition or direction relative to the treating clinician. “Distal” or“distally” are a position distant from or in a direction away from theclinician. “Proximal” and “proximally” are a position near or in adirection toward the clinician. As used herein, with reference to animplanted stented prosthesis, the term “outflow” is understood to meandownstream to the direction of blood flow, and the term “inflow” isunderstood to mean upstream to the direction of blood flow.

As described below, aspects of the present disclosure relate totranscatheter stented prosthesis delivery devices utilizing one or moreelongate tension members (e.g., sutures, cords, wires or filaments) tocompressively retain the stented prosthesis on the delivery deviceduring delivery to a target site. By way of background, generalcomponents of one non-limiting example of a delivery device 10 withwhich some embodiments of the present disclosure are useful areillustrated in FIGS. 1-2B. The delivery device 10 is arranged andconfigured for percutaneously delivering a stented prosthesis 30(schematically illustrated) to a patient's native defective heart valveor other target site. The delivery device 10 includes an optional outersheath assembly 12 having an outer sheath 14, a shaft assembly 16 and ahandle assembly 18. One or more elongate tension members 20 a-c areprovided, and can be considered part of the delivery device 10 in someembodiments or as part of the stented prosthesis 30 in otherembodiments. The delivery device 10 provides a loaded, compressedarrangement (FIG. 2A) in which the stented prosthesis 30 is loaded overand is compressively retained on a distal portion 22 of the shaftassembly 16 by the tension members 20 a-c. As is schematicallyillustrated in FIGS. 2A-2B, compression of the stented prosthesis 30 isadjustable by varying the tension in the one or more tension members 20a-c. In this embodiment, the outer sheath 14 is interconnected to acapsule 24 that is selectively disposed over the compressed stentedprosthesis 30 and assists in constraining the stented prosthesis 30.Once loaded, compressed and optionally sheathed by the capsule 24, thestented prosthesis 30 is delivered to the native defective heart valve.When the stented prosthesis 30 is at the target site, the capsule 24 iswithdrawn and tension in the tension members 20 a-c is lessened orreleased to permit the stented prosthesis 30 to self-expand to anexpanded arrangement, partially releasing and ultimately fully deployingthe stented prosthesis 30 from the shaft assembly 16 (see, FIG. 2B).Movement of the outer sheath 14 and capsule 24 relative to the stentedprosthesis 30 can be actuated by the handle assembly 18. As will bediscussed in detail below, many of the disclosed embodiments arearranged and configured to distribute and balance the tensioning forceapplied to one or more tension members 20 a-c along a length of thetension member and between two or more tension members.

As referred to herein, stented prostheses useful with the variousdevices and methods of the present disclosure may assume a wide varietyof configurations. Stented prostheses can include, for example, stentedprosthetic heart valves (“prosthetic valves”), such as a bioprostheticheart valve having tissue leaflets or a synthetic heart valve havingpolymeric, metallic or tissue-engineered leaflets, and can bespecifically configured for replacing valves of the human heart. Thestented prostheses of the present disclosure may be self-expandable,balloon expandable and/or mechanically expandable or combinationsthereof. In general terms, the prosthetic valves of the presentdisclosure include a stent or stent frame having an internal lumenmaintaining a valve structure (tissue or synthetic), with the stentframe having a normal, expanded condition or arrangement and collapsibleto a compressed condition or arrangement for loading within the deliverydevice. For example, the stents or stent frames are support structuresthat comprise a number of struts or wire segments arranged relative toeach other to provide a desired compressibility and strength to theprosthetic valve. The struts or wire segments are arranged such thatthey are capable of self-transitioning from, or being forced from, acompressed or collapsed arrangement to a normal, radially expandedarrangement. The struts or wire segments can be formed from a shapememory material, such as a nickel titanium alloy (e.g., Nitinol™). Thestent frame can be laser-cut from a single piece of material, or can beassembled from a number of discrete components.

One non-limiting example of the stented prosthesis 30 is illustrated indetail in FIGS. 3A-3B. As a point of reference, the stented prosthesis30 is shown in a normal or expanded arrangement in the view of FIG. 3Aand a compressed arrangement in the view of FIG. 3B. The stentedprosthesis 30 shown in this embodiment is a stented prosthetic heartvalve and includes a stent or stent frame 32 and a valve structure 34.The stent frame 32 can assume any of the forms mentioned above, and isgenerally constructed to be self-expandable from the compressedarrangement to the normal, expanded arrangement. As discussed above,compression of the stented prosthesis 30 can be achieved with one ormore tension members 20 a-c. Three tension members 20 a-c arereferenced, however, the use of fewer or more tension members isenvisioned.

If provided, the valve structure 34 of the stented prosthesis 30 canassume a variety of forms, and can be formed, for example, from one ormore biocompatible synthetic materials, synthetic polymers, autografttissue, homograft tissue, xenograft tissue, or one or more othersuitable materials. In some embodiments, the valve structure 34 can beformed, for example, from bovine, porcine, equine, ovine and/or othersuitable animal tissues. In some embodiments, the valve structure 34 isformed, for example, from heart valve tissue, pericardium, and/or othersuitable tissue. In some embodiments, the valve structure 34 can includeor form one or more leaflets 36. For example, the valve structure 34 canbe in the form of a tri-leaflet bovine pericardium valve, a bi-leafletvalve, or another suitable valve.

In some prosthetic valve constructions, such as that of FIGS. 3A-3B, thevalve structure 34 can comprise two or three leaflets 36 that arefastened together at enlarged lateral end regions to form commissuraljoints, with the unattached edges forming coaptation edges of the valvestructure 34. The leaflets 36 can be fastened to a skirt that in turn isattached to the stent frame 32. The stented prosthesis 30 includes afirst end 40 (inflow), an opposing second end 44 (outflow) and anintermediate section or waist 42. As shown, the stent frame 32 can havea lattice or cell-like structure, and optionally forms or provides posts46 corresponding with commissures of the valve structure 34 as well asfeatures 48 (e.g., crowns, eyelets or other shapes) at the first andsecond ends 40, 44. If provided, the posts 46 are spaced equally aroundframe 32 (only one post 46 is clearly visible in FIG. 3A).

Referring now also to FIG. 4 , which illustrates one way in which thetension members can be positioned or routed around the stentedprosthesis (not shown for ease of illustration). This embodimentincludes an outflow tension member 20 a, waist tension member 20 b andan inflow tension member 20 c, each of which are wrapped around arelease pin 70 and terminate at a respective end 50 a-c, which isinterconnected to a connector 62 of an actuator 60. The release pin 70can be provided, for example, within or along the shaft assembly 16 ofFIG. 1 or as part of a similar device. In this illustrated embodiment,each end 50 a-c is a loop that is connected to the connector 62.Retraction of the actuator 60 proximally when the release pin 70 isengaged with the tension members 20 a-c withdraws and tensions thetension members 20 a-c. It has been observed that very specific orprecise tension member 20 a-c lengths are required in order to achieve auniform crimp of the stented prosthesis. Once the stented prosthesis isdeployed, the release pin 70 can be retracted to disengage from thetension members 20 a-c so that the tension members 20 a-c be fullywithdrawn by the actuator 60 to be removed from the patient. It is notedthat all embodiments disclosed herein that utilize a release pin canoperate in a similar fashion.

Turning now also to FIG. 5 , which illustrates an alternate way in whichtension in an elongate tension member 120 can be tensioned with anactuator 160 having a connector 162 to provide crimping of a stent frameof a stented prosthesis (the stented prosthesis is not shown for ease ofillustration). In this embodiment, one tension member 120 is provided,the tension member 120 capable of being wrapped around the stent framefour times to create four tension loops 121 a-d. The tension member 120includes two looped ends 150 a-b and can be tensioned by proximallyretracting the actuator 160. In this embodiment, the connector 162 is aring or the like at a distal end of the actuator 160. Optionally, thetension member 120 can be configured to limit the length that it canpass or slide within the connector 162. For example, the tension member120 can include an interconnecting member 156 spanning between opposingsides of the tension member 120, for example.

As one example, the tension member 120 is routed as follows. One loopedend 150 a of the tension member 120 can be threaded through the releasepin 70 and then wrapped around the stent frame back and around therelease pin 70 to form a first tension loop 121 a. The tension member120 can then make one more pass around the stent frame to form a secondtension loop 121 b before being routed up through the connector 162 andthen back down to the distal end of the stent frame where the tensionmember 120 is wrapped again around the stent frame to make a thirdtension loop 121 c. The third tension loop 121 c terminates at therelease pin 70, where the tension member 120 again wraps around therelease pin 70 and then around the stent frame to form a fourth tensionloop 121 d positioned between the second and third tension loops 121 b,121 c. The release pin 70 is then positioned within the second loopedend 150 b to secure the tension member 120 to the delivery device andthe stent frame. Some temporary withdrawing and other maneuvering of therelease pin 70 may be required to ultimately obtain the routingconfiguration of FIG. 5 .

Turning now also to FIG. 6 , which illustrates the actuator 160 of FIG.5 used to adjust the tension in a single tension member 220 that isrouted to form two tension loops 221 a-b, each having a double thicknessof tension member material. The tension member 220 is releasablyretained around a stent frame of a stented prosthesis (not shown forease of illustration) with the release pin 70. As with the priorembodiments, movement of the actuator 160 tensions and releases thetension applied by the tension member 220 around the stent frame. Inthis configuration, the tension member 220 can slide and naturallyadjust within the connector 162, thus balancing the tension in eachtension loop 221 a-b. This configuration is particularly useful forshorter prosthetic valves or stent frames and/or if tighter crimpingforce is not required.

Turning now also to FIG. 7 , which illustrates a configuration includingtwo actuators 360 a-b, both of which include respective connectors 362a-b. Each of the actuators 360 a-b is interconnected to one or moreelongate tension members 320 a-d. As with the prior embodiments,proximal/distal movement of the actuator 360 a-b can selectively tensionand release the tension applied to the respective tension member(s) 320a-d. Each of the tension members 320 a-d forms a respective tension looparound a stent frame of a stented prosthesis (not shown for ease ofillustration). In one configuration, a first tension member 320 a isthreaded through one connector 362 a, around the stent frame and aroundthe release pin 70, then back to the connector 362 a, where two ends ofthe elongate tension member 320 a are tied or otherwise connected sothat the tension member 320 a forms a continuous loop of material. Threeadditional elongate tension members 320 b-d are routed around the stentframe and release pin 70 in a similar manner but are tied or otherwiseconnected together distal to the respective connector 362 b. Theconnected ends 350 a-c can be jointly connected to an interconnectingmember 374, which is a loop slidably retained within the connector 362b. The interconnecting member 374 can be considered part of the tensionmembers 320 a-c. By having multiple actuators 360 a-b, if one of theactuators 360 a-b is rendered non-functional, crimping of the stentframe may still be achieved with the other actuator. Additionally,controlled crimping of the stent frame and controlled deployment of thestent frame or prosthetic valve at different levels may be achieved byselectively adjusting the position of each actuator 360 a-b.

Now also referring to FIG. 8 , which illustrates a configuration thatalso includes the two actuators 360 a-b of FIG. 7 . Each of theactuators 360 a-b is interconnected to one or more elongate tensionmembers 420 a-c. As with the prior embodiments, movement of the actuator420 a-c selectively tensions or releases the tension applied to therespective tension member(s) 420 a-c connected thereto. In thisembodiment, each tension member 420 a-c includes two looped ends 450a-f. One looped end 450 a-c of each tension member 420 a-c is releasablysecured to the release pin 70 and then wrapped around the stent frame(not shown for ease of illustration) and then is movably secured to oneof the connectors 362 a-b. In this embodiment, the second looped end 450d-f of each tension member 420 a-c is connected to one respectiveconnectors 362 a-b such that the looped end 450 d-f can slide within andwith respect to one respective connector 362 a-b. In one embodiment, asillustrated, the first actuator 360 a is interconnected to and controlsthe tensioning in two elongate members 420 b-c and the second actuator360 b is interconnected to and controls the tension in one elongatemember 420 a.

Turning now also to FIG. 9 , which illustrates an alternate way in whichtwo elongate tension members 520 a-b can be routed and connected to theactuators 360 a-b of FIGS. 7-8 . In this embodiment, the first tensionmember 520 a is wrapped around a stent frame of a stented prosthesis tworevolutions to create two spaced-apart tension loops 521 a-b and thesecond tension member 520 b being wrapped around the stent frame tworevolutions to create two additional spaced-apart tension loops 523 a-b(the stent frame is not shown for ease of illustration). The tensionmembers 520 a-b each include a looped end 550 a, 550 d slidablyconnected with one respective connector 362 a-b and can be tensionedwith proximal retraction of the respective actuator 360 a-b. Secure andrelease of the tension members 520 a, 520 b with respect to the stentframe can be accomplished with the release pin 70, as discussed abovewith respect to prior embodiments, for example.

Now also referring to FIG. 10 , which illustrates one way in whichelongate tension members 620 a-c can be configured to be tensioned withan actuator 660 and slide within and with respect to the actuator 660such that the tension in and between at least two of the tension members(e.g., tension members 620 a and 620 c) is balanced. In this embodiment,the actuator 660 includes a connector or balancing element 662 havingfirst and second rings 664 a-b to balance the tension in the tensionmembers 620 a, 620 c to provide even crimping of a stent frame of astented prosthesis at the inflow and outflow ends (the stentedprosthesis is not shown for ease of illustration). In this embodiment,three tension members 620 a-c are provided. This embodiment includes anoutflow tension member 620 a, waist tension member 620 b and an inflowtension member 620 c, each of which are wrapped around a release pin 70and terminate at a respective end 652 a-c, which is directly orindirectly interconnected to one ring 664 a-b of the connector 662. Theinterconnecting member 672 is threaded through the ring 664 a to allowthe interconnecting member 672 and tension members 620 a, 620 c to slideand equalize the tension in the outflow and the inflow tension members620 a, 620 c applied by the actuator 660. In this illustratedembodiment, the outflow tension member 620 a and inflow tension member620 c are tied to an interconnecting member 672 with a knot 652 a, 652c. The interconnecting member 672 can be considered part of the tensionmembers 620 a, 620 c. In some embodiments, the knots 652 a, 652 c orother retaining elements are sized such that they cannot pass throughthe ring 664 a as the tension members 620 a, 620 c slide within andadjust with respect to the ring 664 a.

The intermediate tension member 620 b of this embodiment is not balancedwith respect to the other tension members 620 a, 620 c and is onlybalanced along its own length via sliding within the second ring 664 b.The inventors have observed that compressing a waist of a stentedprosthesis generally requires a greater amount of force as compared tothe ends, which would overall increase forces on the system. Therefore,a capsule, such as the capsule 24 of FIG. 1 , can also be relied upon tocompress the waist of the stent frame during delivery. In thisillustrated embodiment, the intermediate tension member 620 b is wrappedaround the release pin 70, stent frame and is connected to the secondring 664 b via a knot 652 b or otherwise for securing the tension member620 b through the second ring 664 b.

Referring now also to FIG. 11 , which illustrates an alternateconfiguration in which three elongate tension members 720 a-c areprovided. Outflow and inflow tension members 720 a, 720 c are threadedaround a stent frame of a stented prosthesis (not shown for ease ofillustration) and wrapped around the release pin 70. Respective ends 752a-b of the outflow and inflow tension members 720 a, 720 c are tied orotherwise connected to opposing ends of an interconnecting member 754,which can be considered a portion of the tension members 720 a, 720 c.The interconnecting member 772 can be made of the same material as thetension members 720 a-c or a different material. In this embodiment, theinterconnecting member 772 is slidably threaded through both rings 664a-b of the balancing element or connector 662. If the tension in theoutflow and inflow tension members 720 a, 720 c becomes uneven, theinterconnecting member 772 will naturally slide within the rings 664 a-bto balance the tension in the two respective tension members 720 a, 720c. If desired, the third, intermediate tension member 720 b is routedthrough a third balancing element 774, around the stent frame, to andaround the release pin 70 and then ends 752 c of the intermediatetension member 720 b are tied together or otherwise connected so thatthe intermediate tension member 720 b forms a loop. In this embodiment,the balancing element 774 is a ring and further interconnects theinterconnecting member 772 and the intermediate tension member 720 b sothat all three tension members 720 a-c are interconnected and can slideand balance tension with respect to one another. As with prior disclosedembodiments, proximal and distal movement of the actuator 760correspondingly tensions and releases tension in the intermediatetension member 720 b uniformly with the outflow and inflow tensionmembers 720 a, 720 c. In this embodiment, all three of the rings 664 a,664 b and 774 allow the tension members 720 a-c to adjust and slide withrespect to each other, thus balancing the tension in each tension member720 a-c.

Turning now also to FIG. 12 , which illustrates a similar configurationas compared to that of FIG. 11 but which includes four tension members820 a-d. In this embodiment, outflow and inflow tension members 820 a,820 c that can be routed around the stent frame (not shown for ease ofillustration) and wrapped around the release pin 70. Respective ends 852a, 852 c of the outflow and inflow tension members 820 a, 820 c are tiedor otherwise connected to opposing ends of an interconnecting member774. The interconnecting member 774 can be considered a portion of thetension members 820 a, 820 c and can be made of the same material as thetension members 820 a-d or a different material. The interconnectingmember 774 is slidably threaded through rings 664 a-b of the connector662. If the tension in the outflow and inflow tension members 820 a, 820c becomes uneven, the interconnecting member 774 will naturally slidewithin the rings 864 a-b to balance the tension in the two respectivetension members 820 a, 820 c. The third and fourth, intermediate tensionmembers 820 b, 820 d are wrapped from through a balancing ring 774,around the stent frame, to and around the release pin 70 and then ends852 b, 852 d of the intermediate tension members 820 b, 820 d are tiedtogether or otherwise connected so that the intermediate tension member820 b, 820 d form respective loops. In this embodiment, the additionalbalancing ring 774 is provided spaced between the first and second rings664 a, 664 b and interconnects the interconnecting member and theintermediate tension members 820 b, 820 d. As with prior disclosedembodiments, proximal and distal movement of the actuator 660correspondingly tensions and releases tension in the intermediatetension members 820 b, 820 d uniformly with the outflow and inflowtension members 820 a, 820 c. In this embodiment, all three of the rings664 a, 664 b and 774 allow the tension members 820 a-d to adjust andslide with respect to each other, thus balancing the tension in eachtension member 820 a-d.

Turning now also to the embodiment of FIGS. 13A-13B, which illustrate aconfiguration similar to that of FIG. 4 . In this embodiment, anactuator 960 includes a balancing element 962 including three rings 964a-c arranged longitudinally along a length of the actuator 960. Therings 964 a-c can be three linearly positioned, rigid openings in theactuator 960, for example. In this configuration, a single elongatetension member 920 is slidably threaded through each of the rings 964a-c and around the release pin 70 to change directions as the tensionmember 920 wraps around the inflow, waist and outflow ends of a stentframe of a stented prosthesis (not shown for ease of illustration). Thetension member 920 therefore wraps around the release pin 70 three timesto change direction as the tension member 920 forms three loops 921 a-chaving a double thickness of material around the stent frame. Two endsof the elongate tension member 920 can be connected with a knot 952 orthe like.

Now also referring to FIG. 14 , which illustrates an alternate way inwhich two elongate tension members 1020 a-b can be secured around astent frame to jointly actuate each of the tension members. FIG. 14shows the distal portion 22 of a delivery device, such as that of FIG. 1. The distal portion 22 includes a plurality of guides 23 a-c positionedalong a length of the distal portion 22. The first tension member 1020 aextends over the first guide 23 a and then around the stent frame 32(shown schematically in phantom) to form a first loop 1021 a. The firsttension member 1020 a then extends proximally to and is wound over thesecond guide 23 b and then around the stent frame 32 to form a secondloop 1021 b. The tension member 1020 a then extends distally to andthrough a balancing element 774, such as that disclosed above, and thenextends proximally to the first end of the tension member 1020 a so thatthe ends 1052 of the tension member 1020 a can be tied or otherwisejoined, as illustrated. The second tension member 1020 b extends aroundthe waist of the stent frame 32 and through the balancing element 774.The distal portion 22 can function as an actuator and is arranged andconfigured to be proximally retracted to tension the first and secondtension members 1020 a-b. Each of the tension members 1020 a-b can slidewithin the balancing element 774 to equalize the tension applied by theactuator (i.e. distal portion 22). This embodiment does not include arelease pin as discussed with respect to other embodiments. Once thestent frame 32 or other stented prosthesis is deployed, the firsttension member 1020 a is severed proximate or at the delivery devicehandle assembly to release the delivery device from the stent frame 32.In this embodiment, the second tension member 1020 b is left within thepatient along with the stent frame 32.

Turning now also to FIG. 15 , which illustrates a configurationsubstantially similar to that of FIG. 14 but including two waist tensionmembers 1020 b-c. In this embodiment, each of the waist tension members1020 b-c are secured through the balancing ring 774 and remain in thepatient, around the stent frame 32, after withdrawal of the deliverydevice.

Now referring additionally to FIG. 16 , which illustrates three elongatetension members 1120 a-c, which can be tensioned independently andindividually by a plurality of respective actuation and releaseassemblies (not shown; actuation and release assemblies can bepositioned within a quick connect or a handle assembly, such as thehandle assembly of FIG. 1 ). In this embodiment, each elongate tensionmember 1120 a-c extends from the respective actuation and releaseassembly (not shown), through independent lumens in a shaft assembly(e.g., the shaft assembly 16 of FIG. 1 ), around the stent frame (notshown for ease of illustration) and then around the release pin 70. Thenthe respective tension member 1120 a-c wraps back around the stent frameand to its actuation and release assembly of the handle assembly. Torelease the tension members 1120 a-c from the stent frame, the releasepin is proximally retracted to disengage from the tension members 1120a-c and one end of each of the tension members 1120 a-c is released sothat the other ends of the tension members 1120 a-c can be proximallyretracted a sufficient amount to withdraw the full length of the tensionmembers 1120 a-c from the patient.

Now additionally referring to FIG. 17 , which illustrates aconfiguration having three elongate tension members 1220 a-c that arenot connected to a release pin as disclosed with respect to priorembodiments. In this embodiment, each tension member 1220 a-c extendsfrom a handle assembly or the like (see, e.g., the handle assembly 18 ofFIG. 1 ), through respective lumens within a shaft assembly (e.g., theshaft assembly 16 of FIG. 1 ) and then wraps around the stent frame (notshown for ease of illustration) and then back to the handle assembly orthe like. In this way, the three tension members 1220 a-c define threeloops around the stent frame. The handle assembly (not shown) caninclude an actuation and release assembly for each tension member 1220a-c that is configured to actuate tensioning adjustment and release ofthe respective tension member 1220 a-c so that each tension member 1120a-c can be withdrawn from the stent frame after deployment of the stentframe. This embodiment is beneficial in that all tension members 1220a-c can be actuated uniformly and individually, to result in a symmetriccrimping of the stent frame. Alternatively, the tension members 1220 a-ccan be tensioned to crimp the ends of the stent frame prior to crimpingthe waist, for example. In other words, tension members 1220 a and 1220c can be selectively tensioned prior to or greater than the tensionmember 1220 b. Since the tension members 1220 a-c are controlled byindividual actuation and release assemblies, control of the tension ineach tension member is individually controlled. Once the stentedprosthesis is deployed, one end of each of the tension members 1220 a-ccan be released so that the tension members 1220 a-c can be withdrawnand unwrapped from the stented prosthesis for removal from the patient.

Referring now in addition to FIGS. 18-19 , which collectively illustrateyet another configuration of how an elongate tension member 1320 can berouted and secured over the distal portion 22 and through windows 25 a-dprovided in the distal portion 22 to compressively secure a stentedprosthesis, such as the stented prosthesis 30 (FIGS. 3A-3B) to thedistal portion 22. The stented prosthesis is not shown in FIGS. 18-19 ,however, various portions of the elongate tension member 1320 are shownin phantom to illustrate dimension if the tension member 1320 was routedaround a stented prosthesis. In this embodiment, the tension member 1320is wound in a double helix pattern (generally from 1 to 2 to 3 to 4 to 5to 6 and so on), one helix at one end of the distal portion 22 (and,thus one end of the stented prosthesis 30) and a second helix at asecond end of the distal portion 22 (and, thus a second end of thestented prosthesis). At a proximal end of the distal portion 22, thetension member 1320 forms a loop 1350, which can be connected to andpulled or pushed by an actuator (not shown) to adjust tension in thetension member 1320 either by proximally retracting or distallyadvancing the actuator, respectively. In this embodiment, each end 1352a-b of the tension member 1320 includes a knot or the like (not shown),which anchors the tension member 1320 against a release pin (not shown)positioned within the distal portion 22. The release pin can be therelease pin 70 disclosed with respect to other embodiments. In thedisclosed embodiment, the anchor points at ends 1352 a-b are locatedsuch that, when a tensioning force is applied to the tension member 1320with the actuator, the inflow and outflow ends of the stent framecompress first, followed by compression of the waist upon furthertensioning of the tension member 1320.

Now turning also to FIG. 20 , which illustrates an additionalconfiguration of how an elongate tension member 1420 can be secured overa distal portion 122 (which can be configured largely similar to thedistal portion 22 disclosed above) and through apertures 125 a-b in thedistal portion 122 to compressively secure a stented prosthesis, such asthe stented prosthesis 30 (FIGS. 3A-3B), to the distal portion 122. Inthis embodiment, the tension member 1420 is routed in a coiledconfiguration, as shown. The stented prosthesis is not shown in FIG. 20, however, various portions of the elongate tension member 1420 areshown in phantom to illustrate dimension if the tension member 1420 wasrouted around a stented prosthesis. This configuration can be describedas include two coils that travel up and down a length of the stentedprosthesis (not shown for ease of illustration). In this embodiment, onecoil formed by the tension member 1420 begins at the proximal end of thestented prosthesis and travels in a coiled pattern distally and is tiedoff at a distal end of the distal portion. The second coil formed by thetension member 1420 begins at the distal end of the distal portion 122and travels in a coiled pattern toward the proximal end of the distalportion 122 and is tied to the release pin proximate the proximal end ofthe distal portion. Each end 1452 a, 1452 b of the tension member 1420includes a knot or is otherwise configured to be secured or anchored tothe release pin 70 positioned within the distal portion, as with theprior disclosed embodiment (schematically illustrated). The tensionmember 1420 further provides a loop 1450 at a proximal end of thetension member 1420 that can be connected to an actuator (not shown) sothat proximal retraction of the actuator translates into proximalretraction of the loop 1450, which correspondingly tensions the tensionmember 1420. As a tensioning force is applied to the loop 1450 by theactuator, the coils formed by the tension member 1420 begin to tightenat the ends of the stented prosthesis first and gradually compress thewaist as further tension is applied by the actuator.

The balancing elements disclosed herein can take a variety ofconfigurations. FIG. 21 illustrates one balancing element that isconfigured to be a ring 1574 that can be used in the embodiments ofFIGS. 11-12 and 14-15 , for example as a general equivalent of balancingelement 774. For example, the ring 1574 can be positioned to interfacebetween one or more tension members 1520 and an interconnecting member1572 of any of the types disclosed above. This configuration resistsbinding of tension members 1520, which can occur when two tensionmembers are directly connected. The ring 1574 can be made of a flattenedcoil or from joining two ends of a wire with welding, for example.Alternatively, the ring 1574 can be stamped and then edges could becoined and electropolished. The ring 1574 can be oval, oblong or kidneyshaped, for example.

An actuator 1660 having an alternate balancing element 1662 isillustrated in FIG. 22 . This actuator 1660 can be used in place of anyactuator disclosed herein such as actuators 160, 360, 660, for example.In this embodiment, the balancing element 1662 includes two rings 1664a, 1664 b (e.g., wire loops) on the end through which one or moretension members 1620 or interconnecting members 1674 can be threaded.The rings 1664 a, 1664 b can be made of wire having a smooth surfacefinish, which allows any tension member(s) 1620 and interconnectingmembers 1674 routed therethrough to easily slide and adjust within therespective rings 1164 a, 1664 b, which is beneficial for balancingtension in and between the tension member(s) 1620. The rings 1664 a,1664 b can optionally include a coating, such as PTFE, to furtherimprove the coefficient of friction. It will be understood in view ofthis disclosure that other balancing elements and rings of thedisclosure can also benefit from such a coating.

Referring now also to FIGS. 23A-23C, which further illustrate analternate actuator 1760 having a balancing element 1762, which includesslots 1764 a, 1764 b separated by a pin 1766 at a distal end of theactuator 1760. The pin 1766 has a smooth rounded surface and canoptionally be rotatable within the connector 1762. One or more tensionelements 1720 a, 1720 b (FIG. 23C) are connected to the actuator 1760either directly or via an interconnecting member 1772 threaded throughthe slot and over the pin 1766. As shown in FIG. 23C, each elongatetension member 1720 a, 1720 b can be tied or otherwise connected to theinterconnecting member 1772, with a knot 1752 a, 1752 b, for example.The interconnecting member 1772 can be considered part of the elongatetension members 1720 a-b. The one or more tension elements 1720 a, 1720b can slide within and with respect to the pin 1766, thus allowingtension and load applied by the actuator 1760 to naturally balance thetension in each tension element 1720 a, 1720 b. In some embodiments, theslots 1764 a, 1764 b are sized and the pin 1766 is positioned such thatthe knots 1752 a, 1752 b of each respective tension and interconnectingmember cannot travel past the pin 1766.

Turning now also to FIG. 24 , which illustrates a distal end of analternate actuator 1860 including a plurality of apertures 1864 (only afew of which are referenced) having beveled, rounded or otherwisesmoothed edges through which tensioning elements or interconnectingmembers disclosed above can be threaded, similar to how the tensionmember 1720 a-b or interconnecting member 1772 is retained within theslots 1764 a, 1764 b of FIGS. 23A-23C. As shown, the apertures in thisembodiment are linearly spaced within the same plane. The apertures 1864may be machined or otherwise formed. The apertures 1864 allow thetensioning members, such as those disclosed herein, to be uniformlyactuated and tensioned and further allows the tension members tonaturally slide within the apertures 1864 and adjust so that the tensionin each of the tension members is equally distributed or balanced.

Referring now also to FIG. 25 , which illustrates a distal end of analternate actuator 1960 including a plurality of offset apertures 1964having beveled, rounded or otherwise smoothed edges through whichtensioning members or interconnecting members, disclosed above, can bethreaded. By offsetting the apertures 1964, the tension members of thetype disclosed herein (not shown in FIG. 25 ) can be spaced so that theydo not contact one another, which minimizes the required lumen size ofthe overall system. The three apertures 1964 can be offset by 120degrees, when there are three tension members, for example. Alternateconfigurations including more or fewer apertures and tension members areenvisioned.

Turning now also to FIGS. 26-27C, which schematically illustrate analternate delivery device 2010 configured for optional staggeredadjustment of tension within a plurality of elongate tension members2020 a-c compressively retaining a stented prosthesis 30 to a spindle2022 of the delivery device 2010. The delivery device 2010 can operateand be configured similar to the delivery device 10 of FIGS. 1-2B in allways except as expressly stated. In this illustrative embodiment, threeelongate tension members 2020 a-c are provided and configured, forexample, as shown in FIG. 17 , however, more or fewer elongate tensionmembers are envisioned. Each elongate tension member 2020 a-c extendsfrom the stented prosthesis 30 within or along a shaft assembly 2016 toa handle assembly 18. The handle assembly 2018 includes three actuationand release assemblies 2019 a-c, one interconnected to each elongatetension member 2020 a-c. In this way, a clinician can control eachelongate tension member 2020 a-c individually. In an alternativeembodiment, three elongate tension members may be provided andconfigured, for example, as shown in FIG. 16 , wherein the threeelongate tension members are interconnected to three actuationassemblies and to a release pin. In this embodiment, a clinician cancontrol the tension of each elongate tension member individually butrelease the three elongate tension members together via a release pin.The stent frame 32 of the prosthesis 30 can be compressed in sections(distal, waist, proximal) to minimize compression force in the shaftassembly 2016 to allow for a more flexible shaft construction. Inaddition, individual elongate tension member 2020 a-c control allows theclinician to anchor the stented prosthesis 30 proximally or distallyfirst by rotating the actuator corresponding to the proximal or distaltension member in order to release the proximal or distal section of theprosthesis first. It will be understood that the number of tensionmembers can vary and, correspondingly, the number of actuation andrelease assemblies can also vary, as desired.

One example procedure is conducted as follows. The stented prosthesis 30is loaded and compressed onto the spindle 2022 of the delivery device2010. Then, the stented prosthesis 30 is delivered via transcatheterprocedure to a native valve V (FIG. 27A). The clinician can release thestented prosthesis 30 by rotating the three actuation and releaseassemblies 2019 a-c until the stented prosthesis 30 is approximately 75%open (expanded) and the valve structure (not visible) functions. Then,tension in the distalmost elongate tension member 2020 a is completelyreleased via actuation and release assembly 2019 a to lightly anchor thestented prosthesis 30 within the native valve V (FIG. 27B). Theclinician can then optionally pull or push the delivery device 2010 tocant, tilt, or pitch the stented prosthesis 30 co-axially. Once thestented prosthesis 30 is positioned, as desired, the clinician releasesall tension in the remaining elongate tension members 2020 b-c viaactuation and release assemblies 2019 b-c, respectively, to allow thestented prosthesis to fully expand (FIG. 27C). If recapture is desired,the clinician, via the appropriate actuation and release assembly 2019a-c, applies tension to the respective elongate tension member 2020 a-cto compress the stented prosthesis 30 in stages where elongate tensionforce is high to minimize shaft assembly 2016 compression and movement.In situations where the elongate tension member force is low, allelongate tension members 2020 a-c can be tensioned at the same time viathe actuation and release assemblies 2019 a-c.

The device of FIGS. 26-27C can also be configured to tension theelongate tension members 2020 a-c individually and also release theelongate tension members 2020 a-c individually via single actuation andrelease assembly (e.g., actuation and release assembly 2019 a). In suchan embodiment, the actuator (e.g., 2019 a) could be configured to moveone elongate tension member 2020 a a predetermined distance, stop, andmove on in sequence to the next elongate tension member 2019 b andcontinue in sequence.

The embodiment of FIGS. 26-27C can optionally incorporate the balancingelements and other aspects of the previously disclosed embodiments tobalance tension in the elongate tension members 2020 a-c. Such balancingelements may be particularly useful in embodiments where multipleelongate tension members are controlled by a single actuation andrelease assembly. For example, in an alternative embodiment (not shown),the delivery device may include two actuator and release assemblieswherein one actuator is interconnected to one elongate tension member,e.g., a distal elongate tension member, while the other actuator isinterconnected to a pair of balanced elongate tension members, e.g., awaist elongate tension member and a proximal elongate tension member.The waist elongate tension member and the proximal elongate tensionmember can be balanced as previously disclosed. In this embodiment, theclinician can release the stented prosthesis by rotating the twoactuation and release assemblies until the stented prosthesis isapproximately 75% open (expanded) and the valve structure functions.Then, tension in the distal elongate tension member is completelyreleased to lightly anchor the stented prosthesis within the nativevalve. The clinician can then optionally pull or push the deliverydevice to cant, tilt, or pitch the stented prosthesis co-axially. Oncethe stented prosthesis is positioned, as desired, the clinician releasesall tension in the remaining two elongate tension members via a singleactuation and release assembly to allow the stented prosthesis to fullyexpand.

Although the present disclosure has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges can be made in form and detail without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A delivery apparatus comprising: a deliverydevice configured to carry a stented prosthesis comprising: a connectorcomprising a first aperture; a first tension member comprising a firstend portion forming a first tension loop and a third tension loop, and asecond end portion forming a second tension loop, wherein the firsttension loop, the second tension loop and the third tension loop areeach configured to encircle the stented prosthesis, and the firsttension member further comprising an intermediate segment positionedbetween the first end portion and the second end portion, wherein theintermediate segment is slidably disposed within the first aperture ofthe connector.
 2. The delivery apparatus of claim 1, further comprisinga stented prosthesis maintained in a collapsed orientation on a distalend portion of a shaft assembly of the delivery device by a tension inthe first tension loop encircling the stented prosthesis, a tension inthe second tension loop encircling the stented prosthesis, and a tensionin the third tension loop encircling the stented prosthesis, whereinslidably disposing the intermediate segment within the first aperture ofthe connector balances a tension between the first tension loop, thesecond tension loop, and the third tension loop.
 3. The deliveryapparatus of claim 2, wherein a release pin releasably engages a firstend of the first end portion of the first tension member and releasablyengages a second end of the second end portion of the first tensionmember to facilitate maintenance of the stented prosthesis in thecollapsed orientation.
 4. The delivery apparatus of claim 3, wherein thetension in the first tension loop, the tension in the second tensionloop, and the tension in the third tension loop are configured to bereleased by disengaging the release pin from at least one of the firstend and the second end of the first tension member.
 5. A deliveryapparatus comprising: a delivery device configured to carry a stentedprosthesis comprising: a connector comprising a first aperture and asecond aperture; a first tension member comprising a first end portionforming a first tension loop configured to encircle the stentedprosthesis, a second end portion forming a second tension loopconfigured to encircle the stented prosthesis, and an intermediatesegment positioned between the first end portion and the second endportion, wherein the intermediate segment is slidably disposed withinthe first aperture of the connector; a balancing ring, wherein theintermediate segment of the first tension member is further slidablydisposed within the second aperture and slidably disposed within thebalancing ring between the first aperture and the second aperture; and asecond tension member comprising a first end portion attached to thebalancing ring and second end portion forming a third tension loopconfigured to encircle the stented prosthesis.
 6. The delivery apparatusof claim 5, further comprising a stented prosthesis maintained in acollapsed orientation on a distal end portion of a shaft assembly of thedelivery device by a tension in the first tension loop encircling thestented prosthesis, a tension in the second tension loop encircling thestented prosthesis, and a tension in the third tension loop encirclingthe stented prosthesis, wherein slidably disposing the intermediatesegment within the first aperture of the connector, within the secondaperture of the connector, and within the balancing ring balances atension between the first tension loop and the second tension loop. 7.The delivery apparatus of claim 6, wherein a release pin releasablyengages a first end of the first end portion of the first tensionmember, releasably engages a second end of the second end portion of thefirst tension member, and releasably engages a second end of the secondend portion of the second tension member to facilitate maintenance ofthe stented prosthesis in the collapsed orientation.
 8. The deliveryapparatus of claim 7, wherein the tension in the first tension loop andthe tension in the second tension loop is configured to be released bydisengaging the release pin from at least one of the first end and thesecond end of the first tension member.
 9. A delivery apparatuscomprising: a delivery device configured to carry a stented prosthesiscomprising: a connector comprising a first aperture and a secondaperture; a first tension member comprising a first end portion forminga first tension loop configured to encircle the stented prosthesis, asecond end portion forming a second tension loop configured to encirclethe stented prosthesis, and an intermediate segment between the firstend portion and the second end portion that is slidably disposed withinthe first aperture of the connector; a balancing ring, wherein theintermediate segment of the first tension member is further slidablydisposed within the second aperture and slidably disposed within thebalancing ring between the first aperture and the second aperture; and asecond tension member comprising a first end portion forming a thirdtension loop configured to encircle the stented prosthesis, the secondtension member comprising a second end portion forming a fourth tensionloop configured to encircle the stented prosthesis, and an intermediatesegment of the second tension member between the first end portion ofthe second tension member and the second end portion of the secondtension member is slidably disposed within the balancing ring.
 10. Thedelivery apparatus of claim 9, further comprising a stented prosthesismaintained in a collapsed orientation on a distal end portion of a shaftassembly of the delivery device by a tension in the first tension loopencircling the stented prosthesis, a tension in the second tension loopencircling the stented prosthesis, a tension in the third tension loopencircling the stented prosthesis, and a tension in the fourth tensionloop encircling the stented prosthesis, wherein slidably disposing theintermediate segment of the first tension member within the firstaperture of the connector, the second aperture of the connector, and thebalancing ring balances a tension between the first tension loop and thesecond tension loop.
 11. The delivery apparatus of claim 10, whereinslidably disposing the intermediate segment of the second tension memberwithin the balancing ring balances a tension between the third tensionloop and the fourth tension loop.
 12. The delivery apparatus of claim 9,further comprising a stented prosthesis maintained in a collapsedorientation on a distal end portion of a shaft assembly of the deliverydevice by a tension in the first tension loop encircling the stentedprosthesis, a tension in the second tension loop encircling the stentedprosthesis, a tension in the third tension loop encircling the stentedprosthesis, and a tension in the fourth tension loop encircling thestented prosthesis, wherein slidably disposing the intermediate segmentof the second tension member within the balancing ring balances atension between the third tension loop and the fourth tension loop. 13.The delivery apparatus of claim 10, wherein a release pin releasablyengages a first end of the first end portion of the first tensionmember, releasably engages a second end of the second end portion of thefirst tension member, releasably engages a first end of the first endportion of the second tension member, and releasably engages a secondend of the second end portion of the second tension member to facilitatemaintenance of the stented prosthesis in the collapsed orientation. 14.The delivery apparatus of claim 13, wherein the tension in the firsttension loop and the tension in the second tension loop is configured tobe released by disengaging the release pin from at least one of thefirst end and the second end of the first tension member.
 15. Thedelivery apparatus of claim 14, wherein the tension in the third tensionloop and the tension in the fourth tension loop is configured to bereleased by disengaging the release pin from at least one of the firstend and the second end of the second tension member.
 16. The deliveryapparatus of claim 13, wherein the tension in the third tension loop andthe tension in the fourth tension loop is configured to be released bydisengaging the release pin from at least one of the first end and thesecond end of the second tension member.